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                                                                    Exhibit 10.3

                       SECOND AMENDMENT TO SECOND AMENDED
                          AND RESTATED CREDIT AGREEMENT

         This SECOND AMENDMENT TO SECOND AMENDED AND RESTATED CREDIT AGREEMENT
(this "SECOND AMENDMENT") is entered into effective as of September 30, 2003
(the "AMENDMENT EFFECTIVE DATE"), among GIANT INDUSTRIES, INC., a Delaware
corporation (the "COMPANY"), the financial institutions from time to time
parties to the Credit Agreement (collectively, the "LENDERS"), and BANK OF
AMERICA, N.A. as administrative agent (the "ADMINISTRATIVE AGENT") for the
Lenders and as a Lender and as Letter of Credit Issuing Bank. Capitalized terms
which are used herein without definition and which are defined in the Credit
Agreement referred to below shall have the meanings ascribed to them in the
Credit Agreement.

         WHEREAS, the Company, the Administrative Agent and the Lenders are
parties to that certain Second Amended and Restated Credit Agreement dated as of
May 14, 2002 and amended by the First Amendment dated October 28, 2002 (the
"CREDIT AGREEMENT"); and

         WHEREAS, the Company desires to modify the Credit Agreement to permit
the Company to enter into certain leases as herein described;

         NOW, THEREFORE, for good and valuable consideration, the receipt and
sufficiency of which is hereby acknowledged, the parties hereto hereby agree as
follows:

SECTION 1. Amendment to Schedule 8.05 of the Credit Agreement. Subject to
satisfaction of the condition precedent set forth in Section 3 of this Second
Amendment, Schedule 8.05 of the Credit Agreement is amended by adding the
following:

                  7. Lease of the headquarters building pursuant to
         sale-leaseback arrangement to be entered into in calendar year 2003.

                  8. Lease of two convenience stores in Flagstaff, Arizona to be
         entered into in calendar year 2003.

         SECTION 2. Representations and Warranties. In order to induce the
Administrative Agent and the Lenders to enter into this Second Amendment, the
Company represents and warrants to the Administrative Agent and to each Lender
that:

         (a)      This Second Amendment, the Credit Agreement as amended hereby
and each Loan Document have been duly authorized, executed and delivered by the
Company and the applicable Loan Parties and constitute their legal, valid and
binding obligations enforceable in accordance with their respective terms
(subject, as to the enforcement of remedies, to applicable bankruptcy,
reorganization, insolvency, moratorium and similar laws affecting creditors'
rights generally and to general principles of equity).

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         (b)      The representations and warranties set forth in ARTICLE VI of
the Credit Agreement are true and correct in all material respects on and as of
the Amendment Effective Date, after giving effect to, as if made on and as of
the Amendment Effective Date.

         (c)      As of the date hereof, at the time of and after giving effect
to this Second Amendment, no Default or Event of Default has occurred and is
continuing.

         (d)      No approval, consent, exemption, authorization or other action
by, or notice to, or filing with, any Governmental Authority is necessary or
required in connection with the execution and delivery of this Second Amendment
or the performance by the Company or any Loan Party of its obligations
hereunder. This Second Amendment has been duly authorized by all necessary
corporate action, and the execution, delivery and performance of this Second
Amendment and the documents and transactions contemplated hereby does not and
will not (a) contravene the terms of the Company's or any Loan Party's
Organization Documents; (b) conflict with or result in any breach or
contravention of, or result in or require the imposition or creation of any Lien
under, any document evidencing any material Contractual Obligation to which the
Company or any Loan Party is a party or any order, injunction, writ or decree of
any Governmental Authority to which the Company or any Loan Party is subject; or
(c) violate any Requirement of Law.

         SECTION 3. Conditions of Effectiveness. The amendments to the Credit
Agreement set forth in SECTION 1 of this Second Amendment shall be effective
upon receipt by the Administrative Agent shall have received counterparts of
this Second Amendment duly executed by the Company, the Loan Parties, the
Administrative Agent, and the Majority Lenders.

         SECTION 4. Costs. The Company agrees to pay on demand reasonable
Attorney Costs of the Administrative Agent and all other costs and expenses of
the Administrative Agent, in connection with the preparation, execution and
delivery of this Second Amendment and any other documents executed in connection
herewith.

         SECTION 5. Effect of Amendment. This Second Amendment (i) except as
expressly provided herein, shall not be deemed to be a consent to the
modification or waiver of any other term or condition of the Credit Agreement or
of any of the instruments or agreements referred to therein and (ii) shall not
prejudice any right or rights which the Administrative Agent, the Issuing Bank
or the Lenders may now have under or in connection with the Credit Agreement, as
amended by this Second Amendment. Except as otherwise expressly provided by this
Second Amendment, all of the terms, conditions and provisions of the Credit
Agreement shall remain the same. It is declared and agreed by each of the
parties hereto that the Credit Agreement, as amended hereby, shall continue in
full force and effect, and that this Second Amendment and such Credit Agreement
shall be read and construed as one instrument. The Company and each of the other
Loan Parties hereby confirm and agree that all Liens and other security now or
hereafter held by the Administrative Agent for the benefit of the Lenders as
security

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for payment of the Obligations are the legal, valid and binding obligations of
the Company and the Loan Parties, remain in full force and effect, are
unimpaired by this Second Amendment, and are hereby ratified and confirmed as
security for payment of the Obligations.

         SECTION 6. Miscellaneous. This Second Amendment shall for all purposes
be construed in accordance with and governed by the laws of the State of New
York and applicable federal law. The captions in this Second Amendment are for
convenience of reference only and shall not define or limit the provisions
hereof. This Second Amendment may be executed in separate counterparts, each of
which when so executed and delivered shall be an original, but all of which
together shall constitute one instrument. In proving this Second Amendment, it
shall not be necessary to produce or account for more than one such counterpart.
This Second Amendment may be delivered by facsimile transmission of the relevant
signature pages hereof.

                         [SIGNATURES BEGIN ON NEXT PAGE]

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         THIS IS A SIGNATURE PAGE TO THE GIANT INDUSTRIES, INC. SECOND AMENDMENT
TO SECOND AMENDED AND RESTATED CREDIT AGREEMENT THE CREDIT AGREEMENT (AS AMENDED
BY THIS SECOND AMENDMENT) AND THE OTHER LOAN DOCUMENTS REPRESENT THE FINAL
AGREEMENT BETWEEN THE PARTIES AND MAY NOT BE CONTRADICTED BY EVIDENCE OF PRIOR,
CONTEMPORANEOUS OR SUBSEQUENT ORAL AGREEMENTS OF THE PARTIES.

         THERE ARE NO UNWRITTEN ORAL AGREEMENTS BETWEEN THE PARTIES.

         IN WITNESS WHEREOF, the parties hereto have caused this Second
Amendment to be duly executed and delivered by their proper and duly authorized
officers as of the date and year first above written.

                                   GIANT INDUSTRIES, INC.

                                   By: /s/ MARK B. COX
                                       ------------------------------
                                       Name: Mark B. Cox
                                       Title: Vice President, Treasurer and CFO

                       [SIGNATURES CONTINUED ON NEXT PAGE]

   THIS IS A SIGNATURE PAGE TO THE GIANT INDUSTRIES, INC. SECOND AMENDMENT TO
                  SECOND AMENDED AND RESTATED CREDIT AGREEMENT

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                                   BANK OF AMERICA, N.A., as Administrative
                                   Agent, as Letter of Credit Issuing Bank and
                                   as a Lender

                                   By: /s/ CLAIRE M. LIU
                                       -----------------------
                                       Claire M. Liu
                                       Managing Director

                       [SIGNATURES CONTINUED ON NEXT PAGE]

   THIS IS A SIGNATURE PAGE TO THE GIANT INDUSTRIES, INC. SECOND AMENDMENT TO
                  SECOND AMENDED AND RESTATED CREDIT AGREEMENT

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                                   BANK OF SCOTLAND

                                   By:  /s/ JOSEPH FRATUS
                                       --------------------------------
                                       Name: Joseph Fratus
                                       Title: First Vice President

                       [SIGNATURES CONTINUED ON NEXT PAGE]

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                  SECOND AMENDED AND RESTATED CREDIT AGREEMENT

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                                   BNP PARIBAS

                                   By:  /s/ MARK A. COX
                                       ---------------------
                                       Name: Mark A. Cox
                                       Title: Director

                                   By:  /s/ GREG SMOTHERS
                                       -----------------------
                                       Name: Greg Smothers
                                       Title: Vice President

                       [SIGNATURES CONTINUED ON NEXT PAGE]

   THIS IS A SIGNATURE PAGE TO THE GIANT INDUSTRIES, INC. SECOND AMENDMENT TO
                  SECOND AMENDED AND RESTATED CREDIT AGREEMENT

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                                   COMERICA BANK-CALIFORNIA

                                   By:  /s/ PETER FITZPATRICK
                                       ---------------------------------
                                       Name: Peter Fitzpatrick
                                       Title: Vice President

                       [SIGNATURES CONTINUED ON NEXT PAGE]

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                  SECOND AMENDED AND RESTATED CREDIT AGREEMENT

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                                   FLEET NATIONAL BANK

                                   By:  /s/ ALLISON I. ROSSI
                                       --------------------------
                                       Name: Allison I. Rossi
                                       Title: Director

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   THIS IS A SIGNATURE PAGE TO THE GIANT INDUSTRIES, INC. SECOND AMENDMENT TO
                  SECOND AMENDED AND RESTATED CREDIT AGREEMENT

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                                   HIBERNIA NATIONAL BANK

                                   By:  /s/ CORWIN DUPREE
                                       -----------------------
                                       Name: Corwin Dupree
                                       Title: Asst. Vice-President

                       [SIGNATURES CONTINUED ON NEXT PAGE]

   THIS IS A SIGNATURE PAGE TO THE GIANT INDUSTRIES, INC. SECOND AMENDMENT TO
                  SECOND AMENDED AND RESTATED CREDIT AGREEMENT

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                                   RZB FINANCE LLC

                                   By:  /s/ CHRISTOPH HOEDEL
                                       ---------------------------------
                                       Name: Christoph Hoedl
                                       Title: Vice President

                                   By:  /s/ ELIZABETH HIRST
                                       --------------------------------
                                       Name: Elizabeth Hirst
                                       Title: Assistant Vice President

                       [SIGNATURES CONTINUED ON NEXT PAGE]

   THIS IS A SIGNATURE PAGE TO THE GIANT INDUSTRIES, INC. SECOND AMENDMENT TO
                  SECOND AMENDED AND RESTATED CREDIT AGREEMENT

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                                   WELLS FARGO BANK, N.A.

                                   By:  /s/ ART KRASNY
                                       --------------------
                                       Name: Art Krasny
                                       Title: Relationship Manager

   THIS IS A SIGNATURE PAGE TO THE GIANT INDUSTRIES, INC. SECOND AMENDMENT TO
                  SECOND AMENDED AND RESTATED CREDIT AGREEMENT

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                           RATIFICATION AND AGREEMENT

         Each of the undersigned Loan Parties hereby consents to and accepts the
terms and conditions of the foregoing Second Amendment and the transactions
contemplated thereby, agrees to be bound by the terms and conditions thereof,
and ratifies and confirms that each of the Loan Documents to which it is a party
is, and shall remain, in full force and effect after giving effect to the
foregoing Second Amendment.

                                   GIANT INDUSTRIES ARIZONA, INC.,
                                   GIANT FOUR CORNERS, INC.,
                                   DEGUELLE OIL COMPANY,
                                   GIANT MID-CONTINENT, INC.,
                                   GIANT STOP-N-GO OF NEW MEXICO, INC.,
                                   SAN JUAN REFINING COMPANY,
                                   CINIZIA PRODUCTION COMPANY,
                                   PHOENIX FUEL CO., INC.,
                                   GIANT PIPELINE COMPANY, and
                                   GIANT YORKTOWN, INC.
                                   as Loan Parties

                                   By:  /s/ MARK B. COX
                                       ---------------------
                                       Name: Mark B. Cox
                                             Vice President, Treasurer and CFO

   THIS IS A SIGNATURE PAGE TO THE GIANT INDUSTRIES, INC. SECOND AMENDMENT TO
                  SECOND AMENDED AND RESTATED CREDIT AGREEMENT